\begin{tikzpicture}
    \tkzDefPoints{0/0/A, 4/0/B}
    \tkzDefPointOnLine[pos=0.618](A,B)  \tkzGetPoint{C}
    \tkzDrawSegments[xianduan={below=0pt}](A,C)
    \tkzDrawSegments[xianduan={below=0pt}](C,B)
    \tkzLabelPoints[above=.5em](A,B,C)
\end{tikzpicture}

